ATLANTA, Georgia (CNN) -- Linda Lewis says that when she had back surgery two years ago, her surgeon didn't do what was best for her health; he did was best for his bank account.

If Linda Lewis had known of her surgeon's financial ties to a device maker, she'd have sought a second opinion.

Lewis, a graduate student who lives in Sherman Oaks, California, says Dr. John Regan, a surgeon in Beverly Hills, put in an artificial disc to help relieve her lower back pain.

"He said my back would be better than ever," said Lewis, 45. "I'm thinking, 'Wow, disc replacement is the best thing since sliced bread.' "

But after the surgery, Lewis says, she ended up in debilitating pain, could walk only with the assistance of a walker and had to have a second procedure to correct the first one.

"I couldn't take enough drugs for the pain," she said. "Having that surgery was the worst decision of my life."

Lewis said she was "livid" when she later found out that Regan had financial ties to the company that makes the disc, saying she believes that those ties prompted Regan to recommend the disc over other treatment options.

In an e-mail to CNN, Regan's office manager said he "is not available for comment."

How likely is it that your doctor has a tie to a company that makes drugs or devices? Very likely, according to Dr. Robert Steinbrook, who wrote an article on doctor/industry ties this month in the New England Journal of Medicine. Watch more on medical marketing and doctors »

"Most physicians in the United States have financial relationships with industry, ranging from the acceptance of meals to the receipt of large sums of money for consulting, speaking, or conducting research," he wrote.

For example, two physicians made more than $8 million each from Dupuy Orthopaedics Inc., which lists the payments on its Web site.

"Consumers should absolutely know where their doctor is coming from," said Steven Findlay, a health care analyst at Consumers Union. "Doctors think they won't be influenced by these financial relationships, but the research shows that they are."

Eric Campbell, an associate professor of health policy at Harvard Medical School, put it a different way.

"Let's say your investment counselor went on a trip to Aruba paid for by a certain company," he said. "Then he comes home and recommends you invest in that company. Wouldn't you be concerned?"

If you want to know whether your doctor has financial ties to industry, and how that might color his or her treatment recommendations, experts have this advice:

Brand-name drugs taken long-term -- antidepressants, for example, or cholesterol drugs -- are often heavily marketed to physicians.

If you're suspicious that your doctor's prescription might be based on ties to a certain company rather than on your health, you can ask questions.

"Ask the doctor what's the scientific evidence for prescribing that particular drug over another one. They must have a scientific reason, especially if it's a high-price brand-name drug instead of a generic," Campbell said.

4. Know when not to worry

Is it worth trying to figure out whether every prescription is based on a tie to a pharmaceutical company?

"There are circumstances where you want to take this extra step, and there are other times where you really don't want to bother," Findlay said.

For example, Findlay says, pharmaceutical companies usually don't heavily market antibiotics; they're taken for short periods of time and aren't usually huge money-makers.

The American Medical Association stresses the need for disclosure of doctor-drug company relationships. "The first priority of physicians is the health and well-being of our patients," said Joseph Heyman, M.D., the AMA's board chair.

Lewis says that if she had known that Regan had financial ties to the Charite disc, she would have sought a second opinion about her back pain.

According to a financial conflict-of-interest disclosure released by the North American Spine Society, Regan received "direct or indirect remuneration" in the form of royalties, consulting fees and research support for staff and materials from DePuy Spine, a division of Johnson & Johnson, which makes the Charite disc.

In addition, Regan and his co-authors "acknowledge a financial relationship" with DePuy Spine in a note in a research study they published last year in The Spine Journal.

Lewis is a plaintiff in a lawsuit against DePuy. A company spokesman declined to comment on the litigation but said the Charite disc "preserves some motion and avoids pain at the donor site."